battery bank sizing

[gww]

What is the smallest 48v bank size needed  that has Two 500w Hugh piggot, 1- fisher and paykel (200w - 300w) and  1- ceiling fan (50w-100w) all hooked to bank?  Hooked with proper dumploads.
100 amp hour batteries?  200 amp hour?
Thank you
gww

PS
grid tie, only worried about overload when grid is down.
also What would be a proper dump load?

[gww]

Ok,  lets try this a different way.  I'll guess what I think I need and you guys please tell me if you see something wrong in my thinking.  I am thinking 10 amp out put per 500w turbine and maby 5 amps for the fisher and paykel and cieling fan turbines.  Roughly 25 amps total charging capacity.  This would be a 25% charging rate for a 100 amp hour battery bank. If I put a 1400w dump load I should have my bases covered. 

Soooo, Is a 25 % charge rate in really decent winds (probly not that often) too high?
If not then my guess Is 100 amp battery bank lead acid.

Please say if this is ok or not?
Thanks
   gww

[Watt]

You haven't said anything about your loads so there will be a LOT of assumptions on my part.

No load, 25 amps will keep a very large battery bank charged ( in float ).  25 amps in say bulk stage at a c-10 charge rate is 250a/h capacity, c-20 is 125a/h capacity and c-25 is 100a/h capacity.  Charge rate depends on your battery manufacture specifications.

This is very vague, as you must know what voltage your system will be capable of to consider charge " Stage ". 

[gww]

Watt
Above I mention grid tie.  I have a duel 3648 gvfx outback on mounting plate and both panels.
Starting out I am not going to connect anything to sub panel. I'm just going to grid feed.  Im worried about protecting the batteries when the electric is out. Am I on the right track?  I read zillions of post on healthy charge rates and I still have a very hard time grasping it.
Does this clear up questions on my loading?  Thank you for your reponce and hopfully for your pateince.
gww
PS
also 2000w now and maby 3500w solar.  The turbines won't turn off during full battery power outage.

[Bruce S]

gww;
What he's asking for and anyone here will need to really help is your load needs when the grid IS down.
The problem or need is how much your total load will be during those times. The numbers are needed to make sure your battery bank is large enough to not die an early death while waiting on the grid to come back up.
Right now Mid-Atlantic folks are still seeing outages even in Chicago (days worth).
SO what we'll need is the total you'll need to keep things running when the grid is o u t
Bruce S

[gww]

bruce
Thank you.  starting out I was just going to live with the outage.  We dont have many and Ive never suplimented power before.  Everything is home built and it may take sometime to install it all and I thought I could get as much running as I go along and maby re-assess my needs after running a bit
thanks
gww

Watt
48 volt turbines and solar at 80v-90v through mx60 cc.  Have not bought the batteries yet.  Is c-25 charge rate bad on most batteries?  That would be in high wind.

[birdhouse]

i'd try and get at c/20 rate or below.    basically, if you bought ( trojan t-105's and wired them all in series, you'd end up with a ~200+ Ah @ 48v bank.  this should work well for a minimal bank to keep a few lights on radio ect. 

your question is still pretty vague.  but i took a stab in the dark!

adam

[Watt]

I totally missed the part regarding grid tie.  As of now, I believe I would have a different reply than above.  Forget the added stress of batteries if you really don't need them.  Do your Outbacks require batteries as a voltage cushion for a somewhat steady input voltage?

I think I would be more inclined to coming up with a scheme which would disconnect solar and latch a shutdown switch to the turbines ( if axial ) and engage the " dump load " for any iron core turbines - if a grid failure occurs.  As I understand your post, you are not worried about back up power anyway.  Or maybe you are as you've mentioned " over load ".   I'm confused, sorry about that.

[gww]

adam
I was thinking more along the line of sams club 6v or marine deap cycle.  I have heard the case being made that car batteries with warrenties are good because if they go bad you can get them replaced.  I bought the outback equiptment used and built everything else and I was thinking of just getting it going to see if all is good and get used to it first.  If it were bad and too costly to fix I may get system without batteries. I dont think this is the case, buttttt. I probly dont know how to ask an informative question. I come by this talent naturally.
Thank you
gww

[gww]

Watt
When I said overload I ment too much power to fast to the batteries causing them harm.  I believe the outback mx60 cc will shut down the solar at float voltage. I was hoping to get by with the morningstar cc and a dumpload for the turbines.  two axial and two ironcore turbines.  I dont believe I am smart enough for the avenues you suggest ergo the effort to match dumploads.
With out an extreem amount of help on shorting cuircits and as an alturnitive will what I'm proposing match my system and work?
Thank you
gww
PS
outback does not work without batteries.

[Watt]

Watt
When I said overload I ment too much power to fast to the batteries causing them harm.  I believe the outback mx60 cc will shut down the solar at float voltage. I was hoping to get by with the morningstar cc and a dumpload for the turbines.  two axial and two ironcore turbines.  I dont believe I am smart enough for the avenues you suggest ergo the effort to match dumploads.
With out an extreem amount of help on shorting cuircits and as an alturnitive will what I'm proposing match my system and work?
Thank you
gww
PS
outback does not work without batteries.

With the current available from those turbines, leaving the solar out of the equation as your mx60 should limit current, I'd say 8 of the 6v Sam's cart batteries would be able to accept an over current for some time.  Battery temps and excessive boiling gassing your electrolyte shouldn't be too big an issue unless you are in a storm event with hours of huge currents.  You may want to consider messaging Ghurd for some advice on a controller he might be able to set you up with.   

As you can tell, I'm a little reluctant to approve your suggested configuration.  At least, you can put in place some safety measures and just give it a try.  There is just too much going on there for me to be comfortable with.  Maybe you can try one thing at a time. 

Best wishes.   

[gww]

Watt
Thank you for your time.  I got all this stuff because Im not at home for anouther 16 months so I am building stuff but not using it.  I am building a ghurd controller for a small 12v system.  I believe I will plan on trying the 8 sams club 6v. and see how it goes.  Im going to keep trying to rapp my mind around all this stuff and maby when I am done I wont have made too many mastakes.  thanks for you help.
gww

[ghurd]

As long as the dump load is big enough to deal with ALL the incoming power, then I do not believe there is a whole lot of concern in a system like this.

As far as gassing should not be an issue because the gassing is based (mostly) on the overvoltage and charge rate.
If the battery is Not overvoltage, and the dump load is big enought, I don't belive short term C/1 charging is very bad.
That is with a controller circuit that is fast enough to deal with everything, meaning NO Relay based "Controllers".

I did some silly (meaning very abusive) stuff to 7AH SLAs when prototyping the ghurd controller.
Charging amps at maybe 1.3C (C/0.75), or more.  Dump loads at 2C (C/0.5), or more.
It would be more silly to undersize a battery bank that much in a real, working, system.
Disclaimer: "As far as I could tell", nothing became warm, the battery was happy, no issues, etc.
Again, that is with a fast controller (NO Relays).  It was to test the circuit(s) and not the battery. 

I still use that battery.
G-

[gww]

Thanks G

gww